Mers-el-Kébir (Arabic: المرسى الكبير, “the Great Harbor”) is a port town in northwestern Algeria, located by the Mediterranean Sea near Oran, in the Oran Province.
Originally a Roman port, Mers-el-Kébir became an Almohad naval arsenal in the 1100s, fell under the rulers of Tlemcen in the 1400s, and eventually became a center of pirate activity around 1492. It was occupied variously by the Ottoman Turks, Portuguese and Spanish, with the Spanish capturing it in 1505 under Cardinal Cisneros and holding it until 1792.
The French occupied it in 1830, and rename it Saint André de Mers-el-Kébir, enhancing the port in 1868 with an eponymous lighthouse, the latter was destroyed during World War II.
Following the German defeat of France in 1940, part of the French fleet holed up in the port. On July 3, 1940, Force H of the British Royal Navy attacked the French fleet at Mers-el-Kébir to stop it falling into German hands.
After World War II, France used its naval base at Mers-el-Kébir to assist in atomic tests. The Évian Accords of March 18, 1962, which recognized Algerian independence, allowed France to maintain its base for 15 years; however, France withdrew within five years.